Case Study: External Cladding Kit
External Cladding Kit
The External Cladding Kit (ECK) is a system with no load-bearing function and is intended for vertical or near-vertical building envelopes. The BioBuild ECK will incorporate a substructure in biocomposites. The general function of the External Cladding Kit is to protect the wall area behind it from direct contact with the exterior environment (rain, snow, wind, impacts). One particular technical challenge for this part is the need to ensure that the edges of the panels do not provide a route for water to enter the composite and wick along the natural fibre reinforcement.
The ECK will be made from flax-PFA panels. The box section will be created by bonding a shaped profile to a flat face. This will provide stiffness and ensure that the outer face remains flat. The profile will be bolted to biocomposite pultrusions which in turn will be bolted to the structure of the building. This will reduce thermal bridging from the outer skin to the inner skin as the biocomposite pultrusion is not a good thermal conductor.
Design drivers and technical requirements:
- Simple substructure, simple (cheap and quick) installation
- Lightweight: no heavier than 30kg (max. weight that can be handled on site by two persons)
- Flatness of the panels: 2mm/m
- Not load-bearing
- Impact resistance Class E4: 343 J
- Design should allow replacement of individual panels
Image courtesy GXN.